Gazeta matematică 2021: Difference between revisions
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== Gazeta Matematică 6-7-8/2021 == | == Gazeta Matematică 6-7-8/2021 == | ||
'''[[E:15990]] (Cristina Vijdeluc și Mihai Vijdeluc)''' | |||
''Aflați numărul'' <math>\overline{xyzt}= \overline{ab}\cdot\overline{ac}</math>, ''știind că'' <math>\overline{a,b}+\overline{a,c}=p^2</math> și <math>\overline{ab}-\overline{ac}=q^2</math>, ''unde p și q sunt numere prime.'' | |||
'''[[E:15991]] (Cristina Vijdeluc și Mihai Vijdeluc, Baia Mare )''' | |||
''Aflați numerele naturale <math>n</math> și <math>\overline{abc}</math> pentru care <math>\overline{abc}\cdot n^4=\overline{3abc}</math>.'' | |||
'''[[E:15992]] (Cristina Vijdeluc și Mihai Vijdeluc)''' | |||
''Aflați numerele naturale <math>x</math> și <math>\overline{abcd}</math> pentru care este adevărată relația <math>5[(\overline{ab}+\overline{cd})(\overline{ad}+\overline{cb})-1]=2022-3^x</math>.'' | |||
== Gazeta Matematică 10/2021 == | == Gazeta Matematică 10/2021 == | ||
Revision as of 08:58, 1 December 2024
Gazeta Matematică 6-7-8/2021
E:15990 (Cristina Vijdeluc și Mihai Vijdeluc)
Aflați numărul Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \overline{xyzt}= \overline{ab}\cdot\overline{ac}} , știind că Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \overline{a,b}+\overline{a,c}=p^2} și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \overline{ab}-\overline{ac}=q^2} , unde p și q sunt numere prime.
E:15991 (Cristina Vijdeluc și Mihai Vijdeluc, Baia Mare )
Aflați numerele naturale Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle n} și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \overline{abc}} pentru care Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \overline{abc}\cdot n^4=\overline{3abc}} .
E:15992 (Cristina Vijdeluc și Mihai Vijdeluc)
Aflați numerele naturale Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x} și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \overline{abcd}} pentru care este adevărată relația Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 5[(\overline{ab}+\overline{cd})(\overline{ad}+\overline{cb})-1]=2022-3^x} .
Gazeta Matematică 10/2021
28163 (Dana Heuberger)
Aflați șirul de numere naturale nenule Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle (a_n)_{n\geq1}} pentru care Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \frac{1}{{(1+a_1) \cdot a_{a_1}}} + \frac{1}{{(1+a_2) \cdot a_{a_2}}} + \ldots + \frac{1}{{(1+a_n) \cdot a_{a_n}}} = \frac{n}{{n+1}}} pentru orice Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle n \geq 1} .
Gazeta Matematică 11/2021
28203 (Dana Heuberger)
Fie Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f: \mathbb{R} \longrightarrow \mathbb{R} } o funcție cu proprietatea
Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathcal{P}: f(f(x)-e^x)=e^{f(x)-e^x} + x} , pentru orice Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x\in \mathbb{R}.}
- Dați un exemplu de funcție cu proprietatea Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathcal{P}} care nu este monotonă.
- Dați un exemplu de funcție cu proprietatea Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathcal{P}} care nu este continuă.
- Fie Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f} o funcție care admite primitive și are proprietatea Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathcal{P}} . Arătați că, dacă Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f(x)\ge e^x} , pentru orice Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x\ge 0} , atunci Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f} este surjectivă.
Gazeta Matematică 12/2021
28208 (Dana Heuberger)
Considerăm pentagonul convex ABCDE înscris într-un cerc și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H_1, H_2, H_3, H_4, H_5} ortocentrele triunghiurilor Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle ACD} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle BDE} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle CEA} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle DAB} , respectiv Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle EBC} . Arătați că, dacă Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H_1H_2 \parallel AB} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H_2H_3 \parallel BC} , Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H_3H_4 \parallel CD} și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H_4H_5 \parallel DE} , atunci Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle ABCDE} și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle H_1H_2H_3H_4H_5} sunt pentagoane regulate.